This translated ctrl-k to "\v", which is a "vertical tab", and ctrl-l
to "\f" and ctrl-g to "\a".
There is no "vertical tab" or "alarm" or "\f" *key*, so these
shouldn't be translated. Just drop these and call them `\ck` and such.
(vertical tab specifically is utterly useless and I would be okay with
dropping it entirely, I have never seen it used anywhere)
* fish_key_reader: Simplify default output
It now only prints the bind statement. Timing information and such is
relegated to a separate "verbose" mode.
* Adjust fish_key_reader docs
* Adjust tests
